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Ortho-Nitro Effect on the Diastereoselective Control in Sulfa-Staudinger and Staudinger Cycloadditions.

ABSTRACT: The ortho-nitro effect was discovered in sulfa-Staudinger cycloadditions of ethoxycarbonylsulfene with linear imines. When an ortho-nitro group is present at the C-aryl substituents of linear imines, the sulfa-Staudinger cycloadditions deliver cis-?-sultams in considerable amounts, together with the predominant trans-?-sultams. In other cases, the above sulfa-Staudinger cycloadditions give rise to trans-?-sultams exclusively. Further mechanistic rationalization discloses that the ortho-nitro effect is attributed to its strong electron-withdrawing inductive effect. Similarly, the ortho-nitro effect also exists in Staudinger cycloadditions of ethoxycarbonyl ketene with the imines. The current research provides further insights into the diastereoselective control in sulfa-Staudinger and Staudinger cycloadditions.

SUBMITTER: Yang Z

PROVIDER: S-EPMC6154622 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

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Ortho-Nitro Effect on the Diastereoselective Control in Sulfa-Staudinger and Staudinger Cycloadditions.

Yang Zhanhui Z Abdellaoui Hassane H He Wei W Xu Jiaxi J

Molecules (Basel, Switzerland) 20170512 5

The ortho-nitro effect was discovered in sulfa-Staudinger cycloadditions of ethoxycarbonylsulfene with linear imines. When an ortho-nitro group is present at the C-aryl substituents of linear imines, the sulfa-Staudinger cycloadditions deliver cis-β-sultams in considerable amounts, together with the predominant trans-β-sultams. In other cases, the above sulfa-Staudinger cycloadditions give rise to trans-β-sultams exclusively. Further mechanistic rational ...[more]

PMID: 28498354

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